Mr Haggan said Mrs Cerqua had dialled 999 to ask for police assistance and during the duration of the call, which was played to the jury, her husband called out to his wife asking for an ambulance before he shouted: "He's stabbed him".

The jury was shown photographs of the kitchen which showed several crushed empty cans of Stella Artois lager alongside party food.

Mr Haggan then described how the defendant fled the property bare-footed and called his girlfriend who took him to a friend's party where he continued to get drunk.

He said: "This is a tragic case. In a nutshell it was New Year's Eve last year, both brothers had been drinking, shortly before 9pm an argument started between the two brothers.

"That argument appears to have turned into a tussle, punches may have been exchanged, at some point this defendant picked up a kitchen knife and he used it to stab his brother Christopher.

"He stayed at that New Year's Eve party until the police traced him to that address and he was arrested on suspicion of murder. By then he was very drunk."

Mr Haggan said that Cerqua inflicted a single stab wound to his brother's lower stomach which was about 17cm deep.

He continued: "Every effort was made to save Christopher's life, in the family home where the paramedics and the consultant attended, in the ambulance on the way to hospital and in the resuscitation unit on arrival but sadly Christopher could not be revived and life was declared extinct at 10.20pm on New Year's Eve."

Mr Haggan said the defendant told police that he had acted in self-defence.

He said: "When he was interviewed by the police, the defendant admitted that he had stabbed his brother, he claimed that his brother was threatening him with a knife, he said he had either taken that knife from his brother or that he picked up another knife and he told the police he had used the knife to defend himself."

Mr Haggan said only one knife was found at the property that could have been involved in the incident.

He said that DNA found on this knife matched both the defendant and his brother because, as identical twins, they shared the same DNA profile.

He continued: "After he had stabbed Christopher, the defendant ran away but he did his best to avoid contact with the police.

"We, the prosecution, say that he knew very well what he had done, he was not acting in self-defence; he deliberately stabbed his brother, almost certainly in a fit of temper after he had been drinking.

"Whether he intended to kill his brother or merely to cause his brother really serious injury we say he is guilty of the offence of murder."

Mr Haggan said that the defendant was arrested at the party at 2.25am and when he arrived at Southampton Central Police Station he said: "Is he dead? You're lying. He can't be. Was it me? Was it me? I can't remember. Is my brother dead?"

Next day he also said to officers: "I killed my fucking brother. I don't want to be here anymore. Nine out of ten times it would be alright. Just my luck he had to die on me."

Cerqua denies a charge of murder and the trial, which is expected to last about two weeks, continues.